Aerospace Blog

I used to fly a Luscombe 8F. Then I took some instruction in the Pitts S2. What a dream!

Balanced light controls, 300+ Hp, constant speed prop, etc. Even with my limited skills I found no surprises in the controls.

Pitts shipped one tack welded? Was that a huge Quality oversight or was the fuselage designed for "tack welding" to keep it flexible?

Inquiring minds want to know.

"Pitts shipped one tack welded?"

Not necessarily: various models were available to be amateur-built purely from plans, or as kits / partial kits, or bought factory-built. Kits may well have included a "fuselage tack-welded in factory jigs" as described in post #4; it is a common option for tube-&-rag construction homebuilts. "Tube-&-rag" is common slang for fabric-covered airplanes built of metal tubing (usually steel), as opposed to fabric-covered wooden structures, "Composite" (fiberglass, carbon fiber, foam, resin in pretty much any combination you can imagine), "Sheet Metal" or "Wood" (both self-explanatory). In the real world, things are almost never quite that simple, and we may find a fuselage of metal tubing with metal coverings around the engine, fabric coverings aft, and a wooden turtledeck. Attached might be wings with wood or metal spars, wood or foam ribs, a sheet metal or aircraft plywood leading edge and fabric over the rest . . . . Pretty much any combination can, and likely has, been used. Even the almost relentlessly "sheet metal" Sonex and RV series may have plastic or composite fairings, wing- and tailfeather-tips, and a wide variety of other materials where their properties are suitable. The Pitts was designed about 70 years ago, yet is still being built and flown - another testament to Curtis Pitts' good work.

Ordinarily, in homebuilding, the tack-welded fuselage and all other structures may be built up to near-complete condition, then the airplane disassembled while final welding is done. This permits relatively easy adjusting of fit and alignment, or even partial re-design to accommodate, say, a different engine than originally used, a wider cockpit, different airfoils, or whatever, before it becomes too difficult to do. With the disassembled components final-welded, NORMALLY there would be an inspection and sign-off for cover; covering of individual portions may be easier than working on a complete plane. It is hard to imagine how a tack-welded fuselage could be overlooked at covering time!

The owner soon discovered that for all these years, the fuselage had been tack-welded.

So is that were AMF went after they left Harley-Davidson?

I'll bet this frame was sold as "Factory jig tack welded" part of a kit. The first (often few) aspirant builder sold it on until some mut went and covered it as is without the welding ever being inspected!!! The builders logs should prevent such an error. Would love to hear from current EAA inspector.

Thank goodness that Pitts was never put through its paces by a top level aerobatics pilot.

As I recall, you could purchase kits in various stages (1980-1990's era).

I know of one aerobatic competitor (national champion level) that built one Pitts a year. He had all his own jigs, and was by profession a fabricator / machinist. His workmanship was flawless.